Abstract

A combined structure and stoichiometry study on the growth behavior of single crystalline Ge(111) layers on heterostructures is presented. Ex situx-ray diffraction techniques indicate that the interaction between Ge and results in a complete reduction of the buffer oxide to a cubic film structure. In situreflection high energy electron diffraction,x-ray and ultraviolet photoelectron spectroscopy studies demonstrate that this chemical reduction of the oxide support occurs during the initial Gegrowth stage. The interaction of with Ge results in the formation of an amorphous Ge oxide layer by the diffusion of lattice oxygen from the dielectric to the forming semiconductor deposit. After the complete conversion of to cubic , the supply of reactive lattice oxygen is exhausted and the continuous Ge deposition reduces the initially formed amorphous -like film to GeO. The sublimation of volatile GeO uncovers the single crystalline cubic filmsurface which provides a thermodynamically stable template for elemental Geheteroepitaxy. A Volmer–Weber growth mode is observed which results after island coalescence in the formation of atomically smooth, single crystalline Ge(111) layers.